Colored Stones 14 - Fancy Sapphires PDF

Colored Stones 14 KEY CONCEPTS Differing amounts and combinations of the trace elements iron, titanium, and chromium cause most fancy sapphire colors. The trace element vanadium causes sapphire’s color change. The finest stars are distinct, centered, and uniform. Padparadschas typically have the high...

Colored Stones 14 KEY CONCEPTS Differing amounts and combinations of the trace elements iron, titanium, and chromium cause most fancy sapphire colors. The trace element vanadium causes sapphire’s color change. The finest stars are distinct, centered, and uniform. Padparadschas typically have the highest per-carat value of all fancy sapphires. Fine pink sapphires regularly command top prices, sometimes comparable to padparadschas. Purple sapphires are often heat-treated to achieve a more valuable pink or red hue. Green sapphire is readily available, but its color isn’t very marketable. At one time, colorless sapphire was marketed as an inexpensive natural substitute for diamond. The typical corundum color change is from blue or violet in daylight to violetish purple to strongly reddish purple in incandescent light. 182 The most valuable star corundum has bodycolor that provides a strong contrast to the star. Star ruby is typically the most valuable star corundum. Blue star sapphires generally cost much less than star rubies of equivalent quality. Sri Lanka produces what some consider the widest range of fancy sapphire colors in the world. Madagascar is a major source of high-quality pink sapphire. Purple sapphires are often heat-treated to achieve a more valuable pink or red hue. Beryllium diffusion of sapphire can produce padparadscha colors as well as highly saturated yellows and oranges.